In a message dated 05/19/2000 8:43:09 AM US Eastern Standard Time,
[log in to unmask] writes:

>
>  My question is: Is there any problem adding Silicone to our process?

Maybe, maybe not.

>  What art the things we need to consider in adding this process?

Graham Naisbitt said it well that no-clean is not no-residue.  We have often
found that low solids flux residues can absorb fluids which contact them,
which is why it is really a bad idea to process OA fluxes after no cleans.

My biggest concern would be the compatibility between the low solids residue
and the solvents of the silicone coating.  The simplest experiment would be
to run some IPC-B-24 test coupons with and without flux and coat them.  Test
them using SIR for a week or so.  If the processed/coated boards come out
with essentially the same results control/coated boards, then the two are
compatible.  I just ran a test for a client recently who did this.  The
processed/coated boards failed almost immediately, compared to the
control/coated boards.  I used IPC-TM-650 method 2.6.3.3 (85/85 for 7 days)
for my testing.  You could also use method 2.6.3.1 (cyclical for 7 days).

Doug Pauls
CSL

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################